1. Field of the Invention
The present invention relates to a process for manufacturing an IC card. More particularly, the present invention relates to a process for manufacturing an IC card having a plane coil in which a conductor line is wound a plurality of times on substantially the same plane, and terminals of the plane coil and electrode terminals of a semiconductor element are electrically connected to each other.
2. Description of the Related Art
As shown in FIG. 15, an IC card is composed of a rectangular plane coil 100, in which a conductor 102 is wound a plurality of times, and a semiconductor element 104. The above plane coil 100 and semiconductor element 104 are disposed between two sheets of resin films 106 made of PVC, on the surfaces of which characters are printed. These two sheets of resin films are bonded to each other by an adhesive layer made of polyurethane resin. The plane coil 100 and semiconductor element 104 are sealed by the adhesive layer.
When the thus formed IC card passes through a magnetic field formed in a card processor, electric power is generated by electromagnetic induction caused in the plane coil 100 of the IC card. Therefore, the semiconductor element 104 is started by electric power generated by electromagnetic induction, so that communication can be made between the semiconductor element 104 of the IC card and the card processor via the plane coil 100 which functions as an antenna.
Concerning the conventional plane coil 100 incorporated into the IC card, there is provided a conventional plane coil formed in such a manner that a covered electric wire is wound a plurality of times.
However, when the plane coil 100 is formed by winding the covered electric wire, it is difficult to reduce the manufacturing cost of the plane coil 100. Also, it is difficult to efficiently mass-produce the IC cards. As a result, it is difficult to promote the spread of the IC cards.
In order to solve the above problems, Japanese Unexamined Patent Publication No. 6-310324 discloses a method of forming a plane coil by means of punching.
As disclosed in the above patent publication, when the plane coil is formed by means of punching, it becomes possible to reduce the cost of the IC card and also it is possible to mass-produce it compared with a conventional IC card, the plane coil of which is made by winding a covered electric wire.
However, it was found that the handling property of the above plane coil formed by means of punching is very low. When no forces are given to the rectangular plane coil 100, which has been formed by punching, from the outside, predetermined intervals are formed between the conductor lines 102 adjacent to each other in the peripheral direction as shown in FIG. 16(a).
However, when external force F is given to the plane coil 100 in the traverse direction as shown in FIG. 16(b), the conductor line 102 is deformed, and short circuits occur when the adjacent conductor lines 102 come into contact with each other.
The above contact of the conductor lines 102 is caused by deformation of the conductor lines 102 themselves, as follows. In the process of manufacturing the IC card, for example, when an external force is given to the plane coil 100 for conveying and accommodating it, the conductor lines 102 are deformed. Also, when the plane coil 100 is disposed between the resin films 106, on one side of which an adhesive layer is provided, an external force generated by a flow of the adhesive is given to the conductor line 102 in the traverse direction, so that the conductor lines 102 are deformed.
Therefore, it is an object of the present invention to provide a method of manufacturing an IC card in which short circuit is seldom caused by deformation of the conductor lines generated by an external force given to the plane coil in the traverse direction when the plane coil is conveyed and accommodated in the process of manufacturing the IC card.
The present inventors made investigation to solve the above problems. As a result, they accomplished the following invention as follows. A tape member is made to adhere to a plurality of portions of the plane coil 100, so that the conductor lines 102 composing the plane coil 100 are kept in such a manner that the respective conductor lines 102 are arranged at predetermined intervals with respect to the adjacent conductor lines 102. Due to the above arrangement of the conductor lines 102, when the plane coil 100 is conveyed and accommodated, it is possible to prevent the occurrence of short circuit caused by deformation of the conductor lines 102.
According to the present invention, there is provided a process for manufacturing an IC card comprising the following steps of: forming a plane coil by etching or punching a thin metal plate so that the plane coil consists of a conductor line wound as several loops in substantially the same plane and has respective terminals; mounting a semiconductor element on the plane coil, the semiconductor element having electrodes, and attaching an adhesive agent or tape to a predetermined area of the plane coil so that adjacent conductor lines in the loops are kept a predetermined gap therebetween; and inserting the plane coil between a pair of films to cover the plane coil therebetween, at least one of the films being provided with adhesive layer on a surface facing to the other film to seal the plane coil with the semiconductor element by attaching the pair of films with respect to each other by means of the adhesive layer.
The process further comprises a following steps of: electrically connecting to the electrodes of the semiconductor element to the respective terminals of the plane coil, after the semiconductor element is mounted on the plane coil and before the plane coil is sealed by the pair of films.
The process further comprises the following steps of: forming an IC card frame by etching or punching a thin metal plate so that the IC card frame comprises at least one plane coil consisting of a conductor line wound as several loops in substantially the same plane and having respective terminals and a frame connected to and spaced by a predetermined distance from the plane coil so as to support the plane coil; and separating the plane coil from the frame.
The separating step comprises a step of: separating individual plane coil from the frame; thereafter the individual plane coil is sealed with the semiconductor element by means of the pair of films.
The plurality of individual plane coils are continuously sealed by means of the pair of films; thereafter the films are cut and separated to obtain individual IC cards.
The process further comprises the following steps of: forming an IC card frame comprising at least one plane coil, at least one inner frame portion and an outer frame portion, the inner and outer frame portions are located inside and outside of the plane coil and connected to and spaced by a predetermined distance from innermost and outermost conductor lines of the plane coil so as to support the plane coil; and separating the plane coil from the inner and outer frame portions.
The process further comprises the following steps of: separating the inner frame portion from the innermost conductor lines of the plane coil, after the adhesive agent or tape is attached to the plane coil; and separating the outer frame portion from the outermost conductor lines of the plane coil, after the plane coil is sealed with the semiconductor element by means of the pair of films.
The process further comprises following steps of: forming an IC card frame by etching or punching a thin metal strip so that the IC card frame comprises a plurality of plane coils continuously arranged in a longitudinal direction of the thin metal strip, each plane coil consisting of a conductor line wound as several loops in substantially the same plane and having respective terminals, a plurality of inner frame portions each located inside an innermost conductor line of the respective plane coil and an outer frame portion located outside outermost conductor lines of the plane coils, the inner and outer frame portions are connected to and spaced by a predetermined distance from innermost and outermost conductor lines of the plane coil so as to support the plane coils; mounting semiconductor elements on the respective plane coils, each semiconductor element having electrodes, and attaching an adhesive agent or tape to a predetermined area of the respective plane coil so that adjacent conductor lines in the loops are kept a predetermined gap therebetween; and separating the individual plane coils from the inner and outer frame portions.
The plane coil forming step comprises: forming a bent portion protruded outward or inward from conductor lines in the respective loops of the plane coil.
The plane coil forming step comprises forming connecting pieces for connecting adjacent conductor lines in the loops of the plane coil to keep a predetermined gap between the adjacent conductor lines; and removing the connecting pieces after the steps of attaching an adhesive agent or tape to the plane coil.
According to another aspect of the present invention, there is provided a process for manufacturing an IC card comprising the following steps of:
forming an IC card frame by etching or punching a thin metal strip so that the IC card frame comprises a plurality of plane coils continuously arranged in a longitudinal direction of the thin metal strip, each plane coil consisting of a conductor line wound as several loops in substantially the same plane and having respective terminals, a plurality of inner frame portions each located inside an innermost conductor line of the respective plane coil and an outer frame portion located outside outermost conductor lines of the plane coils, the inner and outer frame portions being connected to and spaced by a predetermined distance from innermost and outermost conductor lines of the plane coil so as to support the plane coils;
mounting semiconductor elements on the respective plane coils, the each semiconductor element having electrodes, and attaching an adhesive agent or tape to a predetermined area of the respective plane coil so that adjacent conductor lines in the loops are kept a predetermined gap therebetween; and
separating the respective inner frame portions from the respective innermost conductor lines of the respective plane coils of the IC card frame, and thereafter
inserting the IC card frame between a pair of films to cover the respective plane coils therebetween, at least one of the films being provided with adhesive layer on a surface facing to the other film to seal the plane coils with the semiconductor element by attaching the pair of films with respect to each other by means of the adhesive layer; and
separating the outer frame portion from the respective outermost conductor lines of the respective plane coils to obtain an individual IC card.
According to the present invention as mentioned above, when an adhesive member and/or tape member is made to adhere to a predetermined portion of the plane coil formed by the etching or punching of a metallic sheet, it is possible to maintain the state of the conductor lines of the plane coil which are wound at predetermined intervals with respect to the adjacent conductor lines. Due to the above arrangement, when the plane coil is conveyed, even if an external force is given to each conductor line in the traverse direction, the conductor line is seldom deformed. Therefore, it is possible to prevent the occurrence of short circuit caused by the contact of the conductor lines with each other.
In order to prevent the deformation of conductor lines caused by conveyance until the adhesive member and/or tape member is made to adhere to a predetermined portion of the plane coil, it is preferable to form a frame for an IC card, to which the plane coil is partially connected, in the frame formed while a predetermined interval is left between the frame and the plane coil, wherein the frame for an IC card is formed by etching or punching a metal sheet.
When the respective conductor lines, which are adjacent to each other in the inside and the outside direction, are connected with each other by connecting pieces, the respective conductor lines, on the circumference composing the plane coil, can be integrated into one body. Therefore, deformation of the conductor lines can be further prevented.